Process of reconditioning crank-case oil



Patented Jan. 1c, 1928,

UNITED STATES I 1,655,666 PATENT OFFICE.

- LELAND I. ODO'M. OF MEMPHIS, TENNESSEE, ASSIGNOR TO PURITY CHEMICALCOE- PANY, OE MEMPHIS, TENNESSEE, A. CORPORATION OLE TENNESSEE.

PROCESS OF RECONDITIONING CRANK-CASE OIL.

No Drawing.

The present invention relates to the treatment of lubricating oils aftersustained service for the purpose of reconditioning such oils forfurther use. The primary object of 5 the invention isthe provision of anovel process for reconditioning used crank case oils.

Another object of the invention is the pro= vision of such a processwhich includes a refining treatment for varying the viscosity,

gravity, flash and fire tests desired for the product.

Many attempts have heretofore been made seeking the recovery oflubricating oils from used crank case lubricants. Such processes do notgive an eificient product and are not capable of being developed foraltering the characteristics of the produced lubricant as desired. Theprocess contemplated bythe present invention enables,the production ofreconditioned lubricating oils having such characteristics as regards toviscosity, color and the like, which may be controlled as desired.

In the a plication of my process to practies, the oi to be treated,which is mineral lubricating oil which is generally composed of amixture of various oils drained from the crank cases of internalcombustion engines, is placed in a still and the ligher hydrocarbons andfreely volatile contents are topped 01f by heat distillation at atemperature varying from 175 to 195 degrees centigrade depending uponthe specific gravity of the oil treated. The degree of distillation maybe varied as desired to control the characteristics of the residual oilin the still.

At the conclusion of the distillation step the residual oil is drawnfrom the still and cooled by any suitable means, after which it isfiltered. In cooling down the residual oil. I prefer to circulate samethrough a water cooled coil but any other means may be employed asdesired. In the filtration step, the fine metallic particles and foreignbodies present in all used crank case oils are eliminated.

Subse uent to filtration the oil under treatment is urther subjected toa cooling recess to reduce the temperature below 95 egrees centigradewhile at the same time the oil is agitated by any suitable means. Iprefer to accomplish the agitation by passing a blast of air through hebody of the oil, but the process is not limited to this specific mode oftreatment.

equal volume of at about 220 degrees F.

Application filed September 27, 1926. Serial No. 138,128.

When the temperature of oil has been reduced to atmospheric temperatureit is further agitated for a period of approximatel 30 minutes with aquantity of sulphuric aci In this step of the process the color of thefinished product may be regulated and determined, as the color isdependent upon the quantityof acid employed. The eater the quantity ofacid employed, the lighter will be the color of the product. After theacid treatment the oil is washed by violent agitation with anapproximately equal volume of water. After a thorough washing themixture is allowed to settle and the water is then drawn oif.

Subsequently the oil is heated and maintalned at a temperature ofapproximately 200 degrees'centigrade while being violently agitated forabout 30 minutes with a sub- .stantially five per cent water solution ofsodium hydroxide. At the termination of this step the mixture is allowedto settle and the sodium hydroxide solution is drawn ofi.

Subsequently the body of oil is again washed by agitation with anapproximately water is'drawn off and the emulsified oil subjected to theaction of steam heated coils to evaporate ofi the contained water. Thebody of oil is then agitated with some diatomaceous material preferablytullers earth, after which it is filtered to produce a finished productwhich is the reconditioned mineral lubricating oil.

At thetermination of in process the reconditioned oil is capable 0serving all purposes and in the, same degree, as posses by the oilbefore its initial use in service. The process is not to be limited tothe specific treatment described in the practical embodiment of itsprinciples as set forth'herein, and I desire it to be understood thatthe process may be practiced in any way as will fall within the scope ofthe invention as claimed.

I claim:

A process for reconditioning used crank case mineral lubricating oilcontaining diluents, which comprises in successive steps, distilling oilof the low boiling diluents of the oil, cooling and simultaneouslyfiltering the water and after settling the residual 011, further coolingand simultaneously agitating the oil at atemperature below 95 degreesCentigrade, agitating the oil with sulphuric acid for a perlod ofapproximately thirty minutes,wash.1ng the oil in a substantially equalvolume of water, heating the washed oil, agitating the heated oil at atemperature of approximately 200 degrees Centigrade with a solution ofsodium hydr0x ide over a period of approximately thirty minutes, washingthe oil with an approximately equal volume of water, heating the oil andevaporating ofi the intermingled water, subsequently agitating the oilwith diatomaceous earth, and filtering the oil 10 whereby purifiedlubricating oil is produced. In testimony whereof I have aflixed mysignature.

LELAND L. ODOM.

